GB1460359A - Wheel locking mechanism - Google Patents

Abstract

1460359 Vacuum cleaners SUNBEAM CORP 7 May 1974 [14 May 1973] 20049/74 Heading A4F [Also in Division F2] The wheels of a vehicle such as a vacuum cleaner are automatically locked when the vehicle is inclined by more than a predetermined angle, the locking means laying freely when the vehicle is horizontal and moving to the locking position under the influence of gravity. As shown, a vacuum cleaner 20, Fig. 1, includes a canister tank 26 incorporating plastics bumpers 28, a tool-holding and handle assembly 32, the semi-cylindrical walls 64, 66 and two side walls 60, 62 Fig. 2, forming a hose-holding section 33, a flexible hose 72 with plastics coupling members 76, 86 and a detent button 87 on a metal end tube 84, a pair of extension tubes 50, 52, loosely mounted in storage channels 54, 56 respectively and each having an aperture (not shown) to co-operate with detent button 87, a locking control member 80 holding hose 74 in place, a rubber dome 90 having its inner face presented to the suction side of the cleaner and forming an efficiency indicator, a latch 92 for securing a front cap 22, a flex and plug 104 mounted for upward movement only, a front castor 110, a pair of plastics-tyred rear wheels 112, and an automatic brake for the rear wheels. As shown, the brake includes a left hand crank section 202, Fig. 2 inserted through a hole 206, and a similar right-hand section 204, the interior sections 210, 212 being joined by a sleeve 214. The outer end of left-hand section 202 forms an arm 216 covered by a plastics cap 220. In operation, when the vacuum cleaner is located on a stairway as shown in Fig. 3 the brake assembly is pivotted by gravity about the lower edges of holes 206, 208, to position 3, where further clockwise movement is prevented by contact of each cap 220 or 222 with its respective tyre. Only slight movement of the cleaner down the stairs causes the wheels to engage the caps frictionally until they jam the tyres at position C. On movement of the cleaner up the stairs when the brakes are initially in position C, the brakes quickly assume position B and further upward movement of the cleaner is permitted. Excessive application is prevented by a stop member 236. The brake assembly can be disengaged and held so by rotating it counter-clockwise (by one of the caps) until sleeve 214 resiliently deforms, and then rests behind, a resilient nipple 228.